Memory Power-Gating Techniques

ABSTRACT

Various implementations described herein are related to a device having memory circuitry activated by a power-gated supply. The device may include level shifting circuitry that receives a switch control signal in a first voltage domain, shifts the switch control signal in the first voltage domain to a second voltage domain, and provides the switch control signal in the second voltage domain. The device may include power-gating circuitry activated by the switch control signal in the second voltage domain, and the power-gating circuitry may provide the power-gated supply to the memory circuitry to trigger activation of the memory circuitry with the power-gated supply when activated by the switch control signal in the second voltage domain.

BACKGROUND

This section is intended to provide information relevant tounderstanding the technologies described herein. As the section's titleimplies, this is a discussion of related art that should in no way implythat it is prior art. Generally, related art may or may not beconsidered prior art. It should therefore be understood that anystatement in this section should be read in this light, and not as anyadmission of prior art.

In some conventional memory designs, various challenges arise withnon-volatile (NV) applications in reference to data retention. Forinstance, if a core voltage is already powered-up, and then if theperiphery voltage powers-up after that, then the signal to inhibit writeoperations typically takes time to rise-up due to its dependency on theperiphery voltage. As such, retention of data in this scenario cannot besaved with conventional NV memory designs, because it is typicallyindistinguishable from a default operational instance. In this instance,if the core voltage is powered-up, and if the clock is floating, thenthe wordline may be triggered to cause a false write that corrupts datain the NV memory, which will lose its retention property and likelycause damage. Thus, there exists a need to improve the physical layoutof NV memory designs.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of various techniques are described herein withreference to accompanying drawings. It should be understood, however,that the accompanying drawings illustrate only various implementationsdescribed herein and are not meant to limit embodiments of varioustechniques described herein.

FIG. 1 illustrates a diagram of power-gate architecture in accordancewith various implementations described herein.

FIG. 2 illustrates a diagram level shifting circuitry in accordance withvarious implementations described herein.

FIG. 3 illustrates a diagram of voltage tracking circuitry in accordancewith various implementations described herein.

DETAILED DESCRIPTION

Various implementations described herein refer to physical layoutdesigns for implementing power-gating schemes and techniques forefficient applications. For instance, the various power-gating schemesand techniques described herein provide for power-gating architectureand self-deterministic level shifter that are configured to avoid glitchon a wordline while coming out of power down mode and retain retentionproperties of non-volatile memory (NVM). In some implementations, thepower-gating schemes and techniques described herein may provide for adevice having memory circuitry (e.g., NVM) that is activated by apower-gated supply. The device may include level shifting circuitry thatreceives a switch control signal in a first voltage domain, shifts theswitch control signal in the first voltage domain to a second voltagedomain (that is different than the first voltage domain), and providesthe switch control signal in the second voltage domain. Also, the devicemay include power-gating circuitry that is activated by the switchcontrol signal in the second voltage domain, and the power-gatingcircuitry may provide the power-gated supply to the memory circuitry totrigger activation of the memory circuitry with the power-gated supplywhen activated by the switch control signal in the second voltagedomain.

Various implementations of power-gating schemes and techniques will nowbe described in greater detail herein below with reference to FIGS. 1-3.

FIG. 1 illustrates a schematic diagram 100 of power-gate architecture104 in accordance with various implementations described herein.

In various implementations, the power-gate (PG) architecture 104 mayrefer to a system or a device having various integrated circuit (IC)components that are arranged and coupled together as an assemblage orcombination of parts that provide for a physical circuit design andrelated structures. In some instances, a method of designing,fabricating and providing the power-gate architecture 104 as anintegrated system or device may be implemented with various IC circuitcomponents described herein so as to implement various power-gatingschemes and techniques associated therewith. The power-gate architecture104 may be integrated with various computing circuitry and components ona single chip, and also, the power-gate architecture 104 may beimplemented in various embedded systems for various automotive,electronic, mobile and Internet-of-things (IoT) applications, includingremote sensor nodes.

As shown in FIG. 1, the power-gate (PG) architecture 104 may includememory circuitry 108 that is activated by a power-gated supply(pg_vddc). In some instances, the memory circuitry 108 may refer tonon-volatile memory (NVM) circuitry, and in some instances, the NVMcircuitry may be implemented with magneto-resistive random access memory(MRAM) or static random access memory (SRAM).

The memory circuitry 108 may be implemented with one or more core arraysin various layout configurations with each core array having an array ofmemory cells or bitcells. Each bitcell may be configured to store atleast one data bit value (e.g., a data value related to a logical ‘0’ or‘1’). The one or more core arrays may have any number of bitcellsarranged in various configurations, such as, e.g., two-dimensional (2D)memory arrays having any number of columns and any number of rows ofmultiple bitcells, which may be arranged in a 2D grid pattern for readand write memory access operations. Also, each bitcell may beimplemented with any type of memory, including, e.g., MRAM, SRAM, and/orany other type of similar memory. For instance, each bitcell may referto a multi-layer MRAM bitcell having free-layers and pinned layers. Inother instances, each bitcell may refer to a multi-transistor SRAM cell,such as, e.g., any type of complementary MOS (CMOS) SRAM cells, such as,e.g., 4T, 6T, 8T, 10T, or more transistors per bit.

The power-gate (PG) architecture 104 may include level shiftingcircuitry having a first level shifter (LS1) that is configured toreceive a switch control signal (sw_ctrl) in a first voltage domain(vddpe), shift the switch control signal (sw_ctrl) in the first voltagedomain (vddpe) to a second voltage domain (vddce), and also provide theswitch control signal (sw_ctrl) in the second voltage domain (vddce). Insome instances, the first voltage domain (vddpe) may refer to aperiphery voltage domain, and the second voltage domain (vddce) mayrefer to a core voltage domain. The first level shifter (LS1) may becoupled in series with multiple buffers (B1, B2) and power-gatingcircuitry (PG1). The first level shifter (LS1) may be coupled betweenthe source voltage supply (vddce) in the second voltage domain (vddce)and ground (vsse). Also, buffers (B1, B2) may be coupled between thesource voltage supply (vddce) in the second voltage domain (vddce) andground (vsse).

The level shifting (LS) circuitry may include a second level shifter(LS2) that receives a retention control signal (ret_ctrl) in the firstvoltage domain (vddpe), shifts the retention control signal (ret_ctrl)in the first voltage domain (vddpe) to the second voltage domain(vddce), and also provides the retention control signal (ret_ctrl) inthe second voltage domain (vddce). Also, the second level shifter (LS2)may be coupled in series with multiple buffers (B3, B4) and logiccircuitry (106), and the second level shifter (LS2) may be coupledbetween the source voltage supply (vddce) in the second voltage domain(vddce) and ground (vsse). Also, in some instances, buffers (B3, B4) maybe coupled between the source voltage supply (vddce) in the secondvoltage domain (vddce) and ground (vsse).

In some implementations, use of the switch control signal (sw_ctrl) andthe retention control signal (ret_ctrl) may be implemented as follows inTable 1:

TABLE 1 sw_ctrl ret_ctrl Operational Mode 0 0 Shutdown Mode (i.e.,pg_vddc is collapsed) 1 X Functional Mode 0 1 Sleep Mode (i.e., bothvddpe and vddce are powered-up)

The level shifting circuitry may include the logic circuitry 106 thatcouples the power-gated supply (pg_vddc) to ground (vsse) whenactivated. The logic circuitry 106 may include a first transistor (T1)that is activated based on the switch control signal (sw_ctrl) in thesecond voltage domain (vddce) at node (nA). The logic circuitry 106 mayinclude a second transistor (T2) that is activated based on theretention control signal (ret_ctrl) in the second voltage domain (vddce)at node (nF). Transistors (T1, T2) may refer n-typemetal-oxide-semiconductor (NMOS) transistors.

In some instances, the power-gate (PG) architecture 104 may include thepower-gating circuitry (PG1) that is activated (or controlled) by theswitch control signal (sw_ctrl) in the second voltage domain (vddce).The power-gating circuitry (PG1) may be configured to provide thepower-gated supply (pg_vddc) to the memory circuitry 108 so as totrigger activation of the memory circuitry 108 with the power-gatedsupply (pg_vddce) when activated by the switch control signal (sw_ctrl)in the second voltage domain (vddce). The power-gating circuitry (PG1)may be implemented with a p-type metal-oxide-semiconductor (PMOS)transistor.

When activated, the power-gating circuitry (PG1) may provide thepower-gated supply (pg_vddce) in the second voltage domain (vdcce) tothe memory circuitry 108. The power-gating circuitry (PG1) may receive asource voltage supply (vddce) in the second voltage domain (vddce) andmay also provide the power-gated supply (pg_vddce) in the second voltagedomain (vddce) to the memory circuitry 108 based on the source voltagesupply (vddce) in the second voltage domain (vddce). The power-gatingcircuitry (PG1) may include a PMOS transistor that operates as apower-gated switch (or simply, a power-gate) based on receiving theswitch control signal (sw_ctrl) in the second voltage domain (vddce).

In some instances, the first level shifter (LS1) may receive the switchcontrol signal (sw_ctrl) and then provide an output signal to the firstbuffer (B1) at node (nC), and the first buffer (B1) may receive theoutput signal from the first level shifter (LS1) at node (nC) and thenprovide an output signal to the second buffer (B2) at node (nB). Thesecond buffer (B2) may receive the output signal from the first buffer(B1) at node (nB) and then provide an output signal to a gate of thepower-gate (PG1) at node (nA). The second buffer (B2) may provide theoutput signal to a gate of the first transistor (T1) of the logiccircuitry 106 at node (nA). The buffers (B1, B2) may be implemented withinverters.

In some instances, the second level shifter (LS2) may receive theretention control signal (ret_ctrl) and then provide an output signal tothe third buffer (B3) at node (nD), and the third buffer (B3) mayreceive the output signal from the second level shifter (LS2) at node(nD) and then provide an output signal to the fourth buffer (B4) at node(nE). Also, the fourth buffer (B4) may receive the output signal fromthe third buffer (B3) at node (nE) and then provide an output signal toa gate of the second transistor (T2) of the logic circuitry 106 at node(nF). The buffers (B3, B4) may be implemented with inverters.

FIG. 2 illustrates a diagram 200 of level shifting circuitry 204 inaccordance with various implementations described herein.

In various implementations, the level shifting circuitry 204 may referto a system or a device having various integrated circuit (IC)components that are arranged and coupled together as an assemblage orsome combination of parts that provide for a physical circuit layoutdesign and related structures. In some instances, a method of designing,fabricating and providing the level shifting circuitry 204 as anintegrated system or device may include the various IC circuitcomponents described herein so as to thereby implement the variouspower-gating schemes and techniques associated therewith. The levelshifting circuitry 204 may be integrated with various computingcircuitry and related components on a single chip, and the levelshifting circuitry 204 may be implemented in various embedded systemsfor automotive, electronic, mobile and Internet-of-things (IoT)applications, including remote sensor nodes.

As shown in FIG. 2, the level shifting (LS) circuitry 204 may include alevel shifter having data control circuitry 110 that provides activationsignals (1st act signal, 2nd act signal) in the first voltage domain(vddpe). In some instances, the activation signals (1st act signal, 2ndact signal) may include a first activation signal (1st act signal) and asecond activation signal (2nd act signal) that is a complement of thefirst activation signal (1st act signal). The data control circuitry 110may include one or more inverters including a first inverter (I1) and asecond inverter (I2). The first inverter (I1) may receive a data controlsignal (data_ctrl) in the first voltage domain (vddpe) and then providethe first activation signal (1st act signal) in the first voltage domain(vddpe). Also, the second inverter (I2) may receive the first activationsignal (1st act signal) in the first voltage domain (vddpe) and thenprovide a second activation signal (2nd act signal) in the first voltagedomain (vddpe). In some instances, as described herein, the firstvoltage domain (vddpe) may refer to a periphery voltage domain, andalso, the second voltage domain (vddce) may refer to a core voltagedomain.

The level shifting (LS) circuitry 204 may include various logiccircuitry (e.g., combination of 114, 118 and 124, 128) that provides anoutput signal (out) in a second voltage domain (vddce) based on theactivation signals (1st act signal, 2nd act signal) in the first domain(vddpe). In some instances, the logic circuitry (114, 118 and 124, 128)may include first logic circuitry (114, 118) and second logic circuitry(124, 128). The first logic circuitry (114, 118) may include a firstpower-gated switch (P1) and first inversion logic (114: P2, N1, N2) thatare coupled between a source voltage supply (vddce) in the second domain(vddce) and ground (vsse). Also, the second logic circuitry (124, 128)may include a second power-gated switch (P4) and second inversion logic(124: P5, N4) that are coupled between the source voltage supply (vddce)in the second domain (vddce) and ground (vsse).

In some instances, the logic circuitry includes the first power-gatedswitch (1st PGS: 118: P1) and the first inversion logic (1st INV 114)that are coupled in series between the source voltage supply (vddce) andground (vsse). The first power-gated switch (P1) may include PMOStransistor (P1), and the first inversion logic (1st INV 114) may includePMOS transistor (P2) along with NMOS transistors (N1, N2). Also, thelogic circuitry includes the second power-gated switch (2nd PGS: 128:P4) and the second inversion logic (2nd INV 124) that are coupled inseries between the source voltage supply (vddce) and ground (vsse). Thesecond power-gated switch (P4) may include PMOS transistor (P4), and thesecond inversion logic (2nd INV 124) may include PMOS transistor (P5)along with NMOS transistor (N4).

The level shifting (LS) circuitry 204 may include latch circuitry(half-latch 208) that provides a latched control signal (latch ctrlsignal) to a power-gate (e.g., first power-gated switch P1) of the logiccircuitry (114, 118 and 124, 128) based on the activation signals (1stact signal, 2nd act signal) so as to trigger activation of the logiccircuitry (114, 118 and 124, 128) so as to thereby provide the outputsignal (out) in the second voltage domain (vddce). In some instances,the first power-gated switch (P1) may be activated by the latchedcontrol signal (latch ctrl signal), wherein the first inversion logic(114: P2, N1, N2) may be activated by the first activation signal (1stact signal), and wherein the second power-gated switch (P4) may beactivated by the output signal (out), and wherein the second inversionlogic (124: P5, N4) may be activated by the second activation signal(2nd act signal). Also, the second inversion logic (124: P5, N4) mayprovide the latch control signal (latch ctrl signal) as a bufferedactivation signal to the latch circuitry (half-latch 208), and the latchcircuitry 208 may operate as a half-latch that receives the bufferedactivation signal and provides the latched control signal (latch ctrlsignal) to a part of the logic circuitry (118) to activate the firstpower-gated switch (P1).

In some instances, the latch circuitry 208 may have one or moretransistors, such as, e.g., PMOS transistor (P3) and NMOS transistor(N3) that are arranged and configured to operate as a half-latch. Thetransistor (P3) may be coupled between the source voltage supply (vddce)and a gate of transistor (N3), and also, transistor (N3) may be coupledbetween a gate of transistor (P3) and ground (vsse). In addition, thegate of transistor (P3) may be coupled to the gate of transistor (P1),and also, the gate of transistor (N3) may be coupled to the output ofthe first inversion logic 114 and the gate of transistor (P4). The firstinversion logic 114 may provide the output signal (out) to a outputbuffer (I3), which may provide a buffered output (b_out). The buffer(I3) may be implemented with an inverter.

In some instances, the level shifting (LS) circuitry 204 may include afirst clamping transistor (CLP1) that is coupled between a first node(n1) and ground (vsse), wherein the first node (n1) is disposed betweenthe first inverter (I1) of the data control circuitry 110 and the firstinversion logic (114: P2, N1, N2) of the logic circuitry. Also, in someinstances, the level shifting (LS) circuitry 204 may include a secondclamping transistor (CLP2) that is coupled between the source voltagesupply (vddpe) in the first domain (vddpe) and a second node (n2),wherein the second node (n2) is disposed between the second inverter(I2) of the data control circuitry 110 and the second inversion logic(124: P5, N4) of the logic circuitry. Also, the level shifting (LS)circuitry 204 may include at least one capacitor (C1) that is coupledbetween the source voltage supply (vddce) in the first domain (vddce)and the second node (n2).

In some instances, the first clamping transistor (CLP1) may be activatedbased on a first control signal (nlog1) that may be derived from thefirst voltage domain (vddpe) and the second voltage domain (vddce).Also, the second clamping transistor (CLP2) may be activated based on asecond control signal (log1 d) that may be derived from the firstvoltage domain (vddpe) and the second voltage domain (vddce), whereinthe first control signal (nlog1) is different than the second controlsignal (log1 d).

FIG. 3 illustrates a schematic diagram 300 of voltage tracking circuitry304 in accordance with various implementations described herein.

In various implementations, the voltage tracking (VT) circuitry 304 mayrefer to a system or a device having integrated circuit (IC) componentsthat are arranged and coupled together as an assemblage or somecombination of parts that provide for a physical circuit layout designand related structures. In some instances, a method of designing,fabricating, building and providing the voltage tracking (VT) circuitry304 as an integrated system or device may be implemented with the ICcircuit components described herein so as to implement variouspower-gating schemes and techniques associated therewith. Also, thevoltage tracking circuitry 304 may be integrated with computingcircuitry and related components on a single chip, and the voltagetracking circuitry 304 may be implemented in embedded systems forautomotive, electronic, mobile and Internet-of-things (IoT)applications, including remote sensor nodes.

As shown in FIG. 3, the voltage tracking (VT) circuitry 304 may includea voltage tracker having first inversion logic (e.g., combination ofP13, N13, N14) that is coupled between the core voltage (vddce) andground (vsse). The first inversion logic (P13, N13, N14) may beconfigured to provide the first control signal (nlog1) based on an inputsignal (log1). Also, the voltage tracking (VT) circuitry 304 may includeat least one capacitor (C2) that is coupled between the source voltagesupply (vddce) in the second domain (vddce) and the node (nlog1) that iscoupled between transistors (P13, N13) and provides the first controlsignal (nlog1). In some instances, the first inversion logic (P13, N13,N14) may include PMOS transistor (P13), NMOS transistor (N13) and NMOStransistor (N14) that are coupled in series between the source voltagesupply (vddce) and ground (vsse).

The voltage tracking (VT) circuitry 304 may include various input logic(e.g., combination of P11, P12, N11, N12) that is coupled between thecore voltage (vddce) and ground (vsse). In some instances, the inputlogic (P11, P12, N11, N12) may have transistors (P11, N11) coupledtogether such that transistor (P11) is coupled between the core voltage(vddce) and a gate of transistor (N11) and such that transistor (N11) iscoupled between gates of transistors (P11, P12, N12) and ground (vsse).Also, the gates of transistors (P11, P12) are coupled together at node(Io), and transistor (N12) is coupled as a diode between node (Io) andground (vsse). When activated, transistor (P12) provides (or passes) thecore voltage (vddce) as the input signal (log1).

The voltage tracking (VT) circuitry 304 may include second inversionlogic (e.g., combination of P15, P16, N15) that is coupled between theinput signal (log1) and ground (vsse). The second inversion logic (P15,P16, N15) may be configured to receive the first control signal (nlog1)and provide the second control signal (log1 d) when activated by thefirst control signal (nlog1). Also, in some instances, the secondinversion logic (P15, P16, N15) may include PMOS transistor (P15), PMOStransistor (P16) and NMOS transistor (N15) that are coupled in seriesbetween the first control signal (nlog1) and ground (vsse). The voltagetracking (VT) circuitry 304 may include PMOS transistor (P17) that iscoupled between transistor (P15) and ground (vsse), and the gate oftransistor (P17) may be coupled to node (log1 d), which provides thesecond control signal (log1 d) as output from the second inversionlogic.

The voltage tracking (VT) circuitry 304 may include power-gate logic(P14) that is coupled between the periphery voltage (vddpe) and thefirst inversion logic (P13, N13, N14). The power-gate logic (P14) may beactivated by the second control signal (log1 d) to thereby provide theperiphery voltage (vddpe) to the first inversion logic (P13, N13, N14).The first inversion logic (P13, N13, N14) and the power-gate logic (P14)may be coupled together to operate as a voltage level detector 308.

The various power-gating schemes and techniques described herein mayprovide some advantages. For instance, there may be no DC power duringfunctional mode of operation, and also, in some instances, there may beno power sequence that needs to be followed. Also, in some instances,there may be no impact on level shifter delay during functional mode ofoperation. Further, in some instances, based on the periphery voltage(vddpe) level, a delay may be generated between the core voltage (vddce)and the control voltage (log1 d), which may change the input state ofthe level shifter so as to thereby switch the level shifter in adeterministic direction.

It should be intended that the subject matter of the claims not belimited to the implementations and illustrations provided herein, butinclude modified forms of those implementations including portions ofimplementations and some combinations of elements of differentimplementations in accordance with the claims. It should be appreciatedthat in the development of any such implementation, as in anyengineering or design project, numerous implementation-specificdecisions should be made so as to achieve developers' specific goals,such as compliance with system-related and/or business relatedconstraints that may vary from one implementation to another. Also, itshould be appreciated that such a development effort may be complex andtime consuming, but would nevertheless be a routine undertaking ofdesign, fabrication, and manufacture for those of ordinary skill havingbenefit of this disclosure.

Described herein are various implementations of a device having memorycircuitry that is activated by a power-gated supply. The device mayinclude level shifting circuitry that receives a switch control signalin a first voltage domain, shifts the switch control signal in the firstvoltage domain to a second voltage domain, and provides the switchcontrol signal in the second voltage domain. The device may includepower-gating circuitry activated by the switch control signal in thesecond voltage domain, and the power-gating circuitry may provide thepower-gated supply to the memory circuitry to trigger activation of thememory circuitry with the power-gated supply when activated by theswitch control signal in the second voltage domain.

Described herein are various implementations of a level shifter. Thelevel sifter may include data control circuitry that provides activationsignals in the first voltage domain. The level sifter may include logiccircuitry that provides an output signal in a second voltage domainbased on the activation signals in the first domain. The level siftermay include latch circuitry that provides a latched control signal to apower-gate of the logic circuitry based on the activation signals so asto trigger activation of the logic circuitry to thereby provide theoutput signal in the second voltage domain.

Described herein are various implementations of a voltage tracker. Thevoltage tracker may include first inversion logic coupled between a corevoltage and ground, and the first inversion logic may be configured toprovide a first control signal based on an input signal. The voltagetracker may include second inversion logic coupled between the inputsignal and ground, and the second inversion logic may be configured toreceive the first control signal and provide a second control signalwhen activated by the first control signal. The voltage tracker mayinclude power-gate logic coupled between a periphery voltage and thefirst inversion logic. The power-gate logic may be activated by thesecond control signal to thereby provide the periphery voltage to thefirst inversion logic. The first inversion logic and the power-gatelogic may be coupled together so as to operate as a voltage leveldetector.

Reference has been made in detail to various implementations, examplesof which are illustrated in the accompanying drawings and figures. Inthe following detailed description, numerous specific details are setforth to provide a thorough understanding of the disclosure providedherein. However, the disclosure provided herein may be practiced withoutthese specific details. In some other instances, well-known methods,procedures, components, circuits and networks have not been described indetail so as not to unnecessarily obscure details of the embodiments.

It should also be understood that, although the terms first, second,etc. may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms are only used todistinguish one element from another. For example, a first element couldbe termed a second element, and, similarly, a second element could betermed a first element. The first element and the second element areboth elements, respectively, but they are not to be considered the sameelement.

The terminology used in the description of the disclosure providedherein is for the purpose of describing particular implementations andis not intended to limit the disclosure provided herein. As used in thedescription of the disclosure provided herein and appended claims, thesingular forms “a,” “an,” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise. The term“and/or” as used herein refers to and encompasses any and all possiblecombinations of one or more of the associated listed items. The terms“includes,” “including,” “comprises,” and/or “comprising,” when used inthis specification, specify a presence of stated features, integers,steps, operations, elements, and/or components, but do not preclude thepresence or addition of one or more other features, integers, steps,operations, elements, components and/or groups thereof.

As used herein, the term “if” may be construed to mean “when” or “upon”or “in response to determining” or “in response to detecting,” dependingon the context. Similarly, the phrase “if it is determined” or “if [astated condition or event] is detected” may be construed to mean “upondetermining” or “in response to determining” or “upon detecting [thestated condition or event]” or “in response to detecting [the statedcondition or event],” depending on the context. In addition, the terms“up” and “down”; “upper” and “lower”; “upwardly” and “downwardly”;“below” and “above”; and other similar terms indicating relativepositions above or below a given point or element may be used inconnection with some implementations of the various schemes, techniques,methods and/or technologies described herein.

While the foregoing is directed to implementations of various techniquesdescribed herein, other and further implementations may be devised inaccordance with the disclosure herein, which may be determined by theclaims that follow.

Although the subject matter has been described in language specific tostructural features and/or methodological acts, it is to be understoodthat the subject matter defined in the appended claims is notnecessarily limited to the specific features or acts described above.Rather, the specific features and acts described above are disclosed asexample forms of implementing the claims.

1. A device comprising: memory circuitry activated by a power-gatedsupply; level shifting circuitry that receives a switch control signalin a first voltage domain, shifts the switch control signal in the firstvoltage domain to a second voltage domain, and provides the switchcontrol signal in the second voltage domain; and power-gating circuitryactivated by the switch control signal in the second voltage domain,wherein the power-gating circuitry provides the power-gated supply tothe memory circuitry to trigger activation of the memory circuitry withthe power-gated supply when activated by the switch control signal inthe second voltage domain.
 2. The device of claim 1, wherein the firstvoltage domain refers to a periphery voltage domain, and wherein thesecond voltage domain refers to a core voltage domain.
 3. The device ofclaim 1, wherein the power-gating circuitry provides the power-gatedsupply in the second voltage domain.
 4. The device of claim 1, whereinthe power-gating circuitry receives a source voltage supply in thesecond voltage domain and provides the power-gated supply in the secondvoltage domain to the memory circuitry based on the source voltagesupply in the second voltage domain.
 5. The device of claim 1, whereinthe power-gating circuitry comprises a p-type metal-oxide-semiconductor(PMOS) transistor that operates as a power-gate based on receiving theswitch control signal in the second voltage domain.
 6. The device ofclaim 1, wherein the level shifting circuitry comprises a level shifterand multiple buffers coupled in series to the power-gating circuitry. 7.The device of claim 1, wherein the level shifting circuitry furtherreceives a retention control signal in the first voltage domain, shiftsthe retention control signal in the first voltage domain to the secondvoltage domain, and provides the retention control signal in the secondvoltage domain.
 8. The device of claim 7, wherein the level shiftingcircuitry includes logic circuitry that couples the power-gated supplyto ground when activated, wherein the logic circuitry is activated basedon the switch control signal in the second voltage domain and based onthe retention control signal in the second voltage domain.
 9. The deviceof claim 1, wherein the memory circuitry refers to non-volatile memory(NVM) circuitry.
 10. The device of claim 9, wherein the NVM circuitrycomprises magneto-resistive random access memory (MRAM).
 11. A levelshifter comprising: data control circuitry that provides activationsignals in the first voltage domain; logic circuitry that provides anoutput signal in a second voltage domain based on the activation signalsin the first domain; and latch circuitry that provides a latched controlsignal to a power-gate of the logic circuitry based on the activationsignals so as to trigger activation of the logic circuitry to therebyprovide the output signal in the second voltage domain.
 12. The levelshifter of claim 11, wherein the activation signals include a firstactivation signal and a second activation signal that is a complement ofthe first activation signal.
 13. The level shifter of claim 11, whereinthe data control circuitry has a first inverter and a second inverter,and wherein the first inverter receives a data control signal in thefirst voltage domain and provides a first activation signal in the firstvoltage domain, and wherein the second inverter receives the firstactivation signal in the first voltage domain and provides a secondactivation signal in the first voltage domain.
 14. The level shifter ofclaim 13, wherein the logic circuitry includes first logic circuitry andsecond logic circuitry, and wherein the first logic circuitry includes afirst power-gated switch as the power-gate and first inversion logiccoupled in series between a source voltage supply in the second domainand ground, and wherein the second logic circuitry includes a secondpower-gated switch and second inversion logic coupled in series betweenthe source voltage supply in the second domain and ground.
 15. The levelshifter of claim 14, wherein the first power-gated switch is activatedby the latched control signal, wherein the first inversion logic isactivated by the first activation signal, wherein the second power-gatedswitch is activated by the output signal, and wherein the secondinversion logic is activated by the second activation signal.
 16. Thelevel shifter of claim 14, wherein the second inversion logic provides abuffered activation signal to the latch circuitry, and wherein the latchcircuitry operates as a half-latch that receives the buffered activationsignal and provides the latched control signal to the logic circuitry toactivate the first power-gated switch.
 17. The level shifter of claim14, further comprising: a first clamping transistor coupled between afirst node and ground, wherein the first node is disposed between thefirst inverter of the data control circuitry and the first inversionlogic of the logic circuitry; and a second clamping transistor coupledbetween a source voltage supply in the first domain and a second node,wherein the second node is disposed between the second inverter of thedata control circuitry and the second inversion logic of the logiccircuitry.
 18. The level shifter of claim 17, wherein the first clampingtransistor is activated based on a first control signal derived from thefirst voltage domain and the second voltage domain, and wherein thesecond clamping transistor is activated based on a second control signalderived from the first voltage domain and the second voltage domain, andwherein the first control signal is different than the second controlsignal.
 19. The level shifter of claim 11, wherein the first voltagedomain refers to a periphery voltage domain, and wherein the secondvoltage domain refers to a core voltage domain.
 20. A voltage trackercomprising: first inversion logic coupled between a core voltage andground, wherein the first inversion logic is configured to provide afirst control signal based on an input signal; second inversion logiccoupled between the input signal and ground, wherein the secondinversion logic is configured to receive the first control signal andprovide a second control signal when activated by the first controlsignal; and power-gate logic coupled between a periphery voltage and thefirst inversion logic, wherein the power-gate logic is activated by thesecond control signal to thereby provide the periphery voltage to thefirst inversion logic, wherein the first inversion logic and thepower-gate logic are coupled together to operate as a voltage leveldetector.